A prior art device is known from U.S. Pat. No. 6,891,432, which discloses an apparatus for electromagnetic processing. The apparatus comprises a polar transmitter in the form of a processor comprising an analog to digital converter and a rectangular to polar converter. The analog to digital converter digitizes a wave, for example by the use of rectangular coordinates or I,Q data. The rectangular to polar converter receives the I,Q data and translates this data into polar coordinates. The rectangular to polar converter generates a digitized wave in polar coordinates comprising an amplitude characteristic and a phase characteristic. The polar transmitter further comprises a modulator comprising control components such as switching transistors for receiving the amplitude characteristic and comprising transistors used as current sources that receive the phase characteristic. The switching transistors control the current sources.
The US patent further discloses that the control components form a bias network for biasing the current sources and discloses that the phase characteristic drives the current sources. So, the current sources are driven as well as biased. This is a first indication that this prior art is based on bipolar transistor technology. Further, each current source in this US patent comprises two inputs at the left side and one output at the right side. One of these inputs is coupled to an output of a corresponding control component and the other input receives the phase characteristic and the output is coupled to the other outputs of the other current sources. So, in the US patent, the control components form a first stage and the current sources form a subsequent second stage. This is a second indication that this prior art is based on bipolar transistor technology.
The known device is disadvantageous, inter alia, owing to the fact that it is specifically designed for bipolar transistor technology.